Use of general constraint flags in video bitstreams

2. The method of claim 1, wherein the one or more syntax elements further comprises a third syntax element, a value of which plus 1 indicates a number of rectangular slices in each video picture, wherein the third syntax element is constrained to be equal to 0 when the first constraint flag is equal to 1 and the second syntax element is equal to 1, and wherein the second syntax element being equal to 1 indicates that the rectangular slice is in use for each video picture.

3. The method of claim 1, wherein the variable is constrained to be equal to 1 when a second constraint flag indicating whether each video picture in the output layer set contains only one tile is equal to 1, and wherein the second constraint flag being equal to 1 indicates that each video picture in the output layer set contains only one tile.

4. The method of claim 1, wherein the one or more constraint flags further comprise a third constraint flag indicating whether a video picture comprises only one subpicture and whether subpicture information is present, wherein the one or more syntax elements further comprise a fourth syntax element, a value of which plus 1 indicates a number of subpictures in the video picture, wherein the fourth syntax element is constrained to be 0 when the third constraint flag is equal to 1, and wherein the third constraint flag being equal to 1 indicates that the video picture comprises only one subpicture and the subpicture information is not present.

5. The method of claim 1, wherein the conversion comprises encoding the video into the bitstream.

6. The method of claim 1, wherein the conversion comprises decoding the video from the bitstream.

8. The apparatus of claim 7, wherein the one or more syntax elements further comprises a third syntax element, a value of which plus 1 indicates a number of rectangular slices in each video picture, wherein the third syntax element is constrained to be equal to 0 when the first constraint flag is equal to 1 and the second syntax element is equal to 1, and wherein the second syntax element being equal to 1 indicates that the rectangular slice is in use for each video picture.

9. The apparatus of claim 7, wherein the variable is constrained to be equal to 1 when a second constraint flag indicating whether each video picture in the output layer set contains only one tile is equal to 1, and wherein the second constraint flag being equal to 1 indicates that each video picture in the output layer set contains only one tile.

10. The apparatus of claim 7, wherein the one or more constraint flags further comprise a third constraint flag indicating whether a video picture comprises only one subpicture and whether subpicture information is present, wherein the one or more syntax elements further comprise a fourth syntax element, a value of which plus 1 indicates a number of subpictures in the video picture, wherein the fourth syntax element is constrained to be 0 when the third constraint flag is equal to 1, and wherein the third constraint flag being equal to 1 indicates that the video picture comprises only one subpicture and the subpicture information is not present.

11. The apparatus of claim 7, wherein the apparatus is an encoder.

12. The apparatus of claim 7, wherein the apparatus is a decoder.

14. The non-transitory computer-readable storage medium of claim 13, wherein the one or more syntax elements further comprises a third syntax element, a value of which plus 1 indicates a number of rectangular slices in each video picture, wherein the third syntax element is constrained to be equal to 0 when the first constraint flag is equal to 1 and the second syntax element is equal to 1, and wherein the second syntax element being equal to I indicates that the rectangular slice is in use for each video picture.

15. The non-transitory computer-readable storage medium of claim 13, wherein the variable is constrained to be equal to 1 when a second constraint flag indicating whether each video picture in the output layer set contains only one tile is equal to 1, and wherein the second constraint flag being equal to 1 indicates that each video picture in the output layer set contains only one tile.

16. The non-transitory computer-readable storage medium of claim 13, wherein the one or more constraint flags further comprise a third constraint flag indicating whether a video picture comprises only one subpicture and whether subpicture information is present, wherein the one or more syntax elements further comprise a fourth syntax element, a value of which plus 1 indicates a number of subpictures in the video picture, wherein the fourth syntax element is constrained to be 0 when the third constraint flag is equal to 1, and wherein the third constraint flag being equal to 1 indicates that the video picture comprises only one subpicture and the subpicture information is not present.

18. The non-transitory computer-readable recording medium of claim 17, wherein the one or more syntax elements further comprises a third syntax element, a value of which plus 1 indicates a number of rectangular slices in each video picture, wherein the third syntax element is constrained to be equal to 0 when the first constraint flag is equal to 1 and the second syntax element is equal to 1, and wherein the second syntax element being equal to I indicates that the rectangular slice is in use for each video picture.

19. The non-transitory computer-readable recording medium of claim 17, wherein the variable is constrained to be equal to 1 when a second constraint flag indicating whether each video picture in the output layer set contains only one tile is equal to 1, and wherein the second constraint flag being equal to 1 indicates that each video picture in the output layer set contains only one tile.

20. The non-transitory computer-readable recording medium of claim 17, wherein the one or more constraint flags further comprise a third constraint flag indicating whether a video picture comprises only one subpicture and whether subpicture information is present, wherein the one or more syntax elements further comprise a fourth syntax element, a value of which plus 1 indicates a number of subpictures in the video picture, wherein the fourth syntax element is constrained to be 0 when the third constraint flag is equal to 1, and wherein the third constraint flag being equal to 1 indicates that the video picture comprises only one subpicture and the subpicture information is not present.